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Minimum time trajectory optimization of a tail-sitter aerial vehicle using nonlinear programming
, Article 2012 International Conference onAdvanced Mechatronic Systems, ICAMechS 2012 ; 2012 , Pages 275-280 ; 9780955529382 (ISBN) ; Assadian, N ; Saghafi, F ; Sharif University of Technology
2012
Abstract
Aerial tail-sitters have drawn many attentions in recent years. The main challenge of employing these vehicles is to ensure safe and efficient takeoff and landing. The aim of the current study is to develop a gradient-base optimization algorithm for a jet aerial tail-sitter in order to obtain minimum time trajectories in transition flight phases. The vehicle is supposed to utilize thrust vectoring system instead of conventional control surfaces that will pose minimal drawbacks in terms of low speed efficiency and complexity. The time-optimal trajectories are computed using the nonlinear dynamic equations of motion of the vehicle in order to make sure that the vehicle can follow the optimum...
Transition flight feasibility of a fluidic thrust vectored aerial tail-sitter: Numerical approach
, Article 2007 ASME Turbo Expo, Montreal, Que., 14 May 2007 through 17 May 2007 ; Volume 1 , 2007 , Pages 229-235 ; 079184790X (ISBN); 9780791847909 (ISBN) ; Banazadeh, A ; Sharif University of Technology
2007
Abstract
This paper describes a feasibility study of using numerical analysis technique, coupled with a non-linear simulation model of a conceptual fluidic-thrust-vectored unmanned aerial tailsitter to obtain required thrust deflection angles for a transition manoeuvre in take-off. It also studies the aircraft behaviour in transition subjected to the changes in specified parameters like the thrust value and the engine distance from the centre of gravity. The focus of the research presented was to get the vehicle from zero speed on the ground, in vertical position, to a specified velocity at a specified attitude, in cruise position. It was also specified that, when the vehicle was considered to be...
Transition Flight Control of a Tilt Tri-Rotor UAV Using Robust Model Predictive Control
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor) ; Emami, Ali (Co-Supervisor)
Abstract
The purpose of this thesis is to control altitude and attitude of a Tilt Tri-Rotor UAV in rotorcraft mode and control of altitude, attitude and forward velocity in transition mode (from rotorcraft mode to cruise) by using model predictive control. First, the detailed mathematical model is obtained by the Newton-Euler equations of motion, in both rotorcraft and transition modes. In the next step, a MIMO model predictive controller has been designed, considering input constraints. Then, since, robustness of the model-based control approach is an important challenge, the performance of the controller is presented in the presence of model uncertainties and wind disturbances. The results indicate...